Bertoldo I d'Este

Bertoldo I d'Este (died 21 July 1343), a son of Francesco d'Este and Orsina Orsini, was marquis of Este from 1317 and took part in the government of Ferrara with his brother Azzo IX, though omitted from the family's imperial investiture of 1323. In 1333 his cousin Rinaldo II d'Este knighted him; he was lord of Ariano.

He married Domenica Pio in 1324 and Caterina da Camino in 1339, and his son by Domenica, Francesco (1325–1384), succeeded him as marquis.